Engineering topics

Golden, R. L.

Publications and source records attributed to Golden, R. L..

At least 37 records · Page 2

NASA NTRS1980

Emulsion chamber observations of primary cosmic-ray electrons in the energy range 30-1000 GeV

The results of a series of emulsion exposures, beginning in Japan in 1968 and continued in the U.S. since 1975, which have yielded a total balloon-altitude exposure of 98,700 sq m sr s, are presented. The data are discussed in terms of several models of cosmic-ray propagation. Interpreted in terms of the energy-dependent leaky-box model, the spectrum results suggest a galactic electron residence time of 1.0(+2.0, -0.5) x 10 to the 7th yr, which is consistent with results from Be-10 observations. Finally, the possibility that departures from smooth power law behavior in the spectrum due to individual nearby sources will be observable in the energy range above 1 TeV is discussed.

Nishimura, J.↗

NASA NTRS1980

Solar modulation of protons and alpha particles at rigidities of 4-10 GV/c

The high statistics and high resolution rigidity spectra from geomagnetic cutoff to 160 GV/c were provided by a superconducting-magnet spectrometer flown on a balloon. The spectra above 8.3 GV/c fit a power law in rigidity for protons and alphas; below 8.3 GV/c, no clear evidence of solar modification is available. The analysis of data from 5.5 to 8.3 GV/c by the Gleeson-Axford model for solar modulation indicated that the modulation parameter was 0.3 + or - 0.05 Gev/nucleon; the spectra below 5.5 GV/c are being analyzed using a portion of the flight data recorded while the balloon was essentially stationary

Badhwar, G. D.↗

NASA NTRS1979

Evidence for the existence of cosmic-ray antiprotons

A search for cosmic-ray antiprotons was recently performed with the use of a balloon-borne superconducting-magnet spectrometer. A total of 46 antiproton candidates were observed in the rigidity interval from 5.6 to 12.5 GV/c. Of these events 18.3 are expected to be atmospheric and instrumentation background. The p(-)/p ratio is found to be 0.00052 + or - 0.00015. This ratio is consistent with secondary production of antiprotons in the interstellar medium.

Golden, R. L.↗

NASA NTRS1978

Relative abundance of antiprotons and antihelium in the primary cosmic radiation

The paper reports measurement of the antiproton-to-proton and antihelium-to-helium ratios in the 4-100 GeV/c range. A superconducting magnet spectrophotometer obtained the data during a balloon flight in May 1976. The upper limit value for the antiproton ratio is 0.0005 in the 4.2-12.5 GeV/c range. This value is only slightly higher than the expected value for a leaky box-model and nearly equal to the value expected in the Peter-Westergard model. It is suggested that this upper limit value rules out the closed galaxy model. Upper limit values for the antihelium ratio are 0.000058 in the 4-10 GeV/c range; less than 0.0001 in the 4-33 GeV/c range; and less than 0.01 in the 33-100 GeV/c range. The interpretation of the raw data is explained.

Badhwar, G. D.↗

NASA NTRS1978

The proton and helium rigidity spectra from 10 to 50 GV

A magnet spectrometer flown from Palestine, Texas, (September 15, 1976) has produced measurements on 150,000 protons and 20,000 helium nuclei covering the rigidity range 10-50 GV. In this interval, the proton spectrum has been fitted to a power law with a spectral index of 2.51 + or - 0.03. Similarly, the helium-nuclei rigidity spectrum can be represented as a power law with an index of 2.61 + or - 0.03.

Badhwar, G. D.↗

NASA NTRS1978

High energy primary electron spectrum observed by the emulsion chamber

A detector of the emulsion chamber type is used to measure the energy spectrum of cosmic-ray electrons. Two large emulsion chambers, each having an area of 40 by 50 sq cm, are exposed for about 25.5 hr at an average pressure altitude of 3.9 mbar. About 500 high-energy cascades (no less than about 600 GeV) are detected by searching for dark spots on the X-ray films. A power-law energy dependence formula is derived for the spectrum of primary cosmic-ray electrons in the energy region over 100 GeV. The results are in good agreement with the transition curves obtained previously by theoretical and Monte Carlo calculations.

Nishimura, J.↗

NASA NTRS1978

The proton and helium rigidity spectra from 10 to 100 GV

An airborne superconducting magnet spectrometer was used to obtain measurements on 700,000 protons and 50,000 helium nuclei of rigidity greater than about 4 GV. The rigidity spectra of protons and helium nuclei in the 9-100 GV range are determined. In the cited range, the proton and helium nuclei can be represented by a power law in rigidity, with an index of 2.78 + or - 0.03 and 2.80 + or - 0.03 respectively. An upper limit on H-2/p of 10% at 35 GeV/nucleon is established

Badhwar, G. D.↗

NASA NTRS1977

The cosmic-ray antiproton flux - An upper limit near that predicted for secondary production

Data gathered from a balloon flight of a superconducting-magnet spectrometer have been examined for the presence of cosmic-ray antiprotons. The ratio of antiprotons to protons, p(-)/p, in cosmic rays was found to be (0.03 + or - 3.3) ten-thousandths in the rigidity interval from 4.2 to 12.5 GV. The 95%-confidence-level upper limit for p(-)/p is thus 0.00066. This upper limit is in strong contradiction to the prediction of the closed-galaxy model of Rasmussen and Peters (1975), but is not inconsistent with the prediction of the modified closed-galaxy model of Peters and Westergaard (1977). It is nearly equal to the predictions of conventional propagation models. This result provides an independent confirmation of the absence of primary antimatter in the cosmic rays at a level of approximately a few ten-thousandths.

Badhwar, G. D.↗

NASA NTRS1977

Analytic representation of the proton-proton and proton-nucleus cross-sections and its application to the sea-level spectrum and charge ratio of muons

We have calculated the sea-level differential muon momentum spectrum and their charge ratio from 1 GeV/c to 5000 GeV/c, using all of the available accelerator data. We find an excellent agreement between our calculation and the existing experimental data. We see no need, at present, to invoke any change either in the cosmic-ray chemical composition or in the nature of the hadron-nucleus interaction at hadron energies above 1500 GeV.

Badhwar, G. D.↗

NASA NTRS1976

Kinematical constraints on the observation of slow monopoles at the top of the atmosphere

Relativistic kinematics of monopole production and propagation in earth's atmosphere and magnetic field have been examined in the light of the observation of a magnetic monopole by Price et al. It has been shown that the observed monopole cannot result from nuclear interactions in the atmosphere and that the extraterrestrial origin of this monopole is very unlikely.

Badhwar, G. D.↗

NASA NTRS1975

Cosmic ray antiproton and positron production in the interstellar medium

We have calculated the energy spectra of cosmic ray secondary antiprotons and positrons using the latest available data on inclusive reactions. Using the measured positron spectrum, we have found that the amount of matter traversed by the cosmic rays in the few GeV region to be 4.7 (+ or - 1.5) g/sq cm of interstellar hydrogen. The computed antiproton to proton ratio is about .0004 for energies 5-10 GeV. This is sufficient to make observations of antiprotons feasible from balloon flights. We have also pointed out the type of information that can be obtained if accurate information of the spectra of these two components becomes available.

Badhwar, G. D.↗

NASA NTRS1975

Superconducting magnets for space flight

The operating principle and application of superconducting magnetic spectrometers for cosmic ray analysis are described. Magnetic spectrometer experiments are thought to be possible in the areas of charge composition and its possible energy dependence, isotopic separation up to several GeV/n, electrons and positrons energy spectra, galactic secondary antiprotons, searches for primordial antimatter, searches for substructure in energy spectra, and gamma ray astronomy. Operational problems associated with the magnets are discussed, and a possible shuttle payload is also described.

Golden, R. L.↗

NASA NTRS1975

A formalism for cosmic ray propagation studies

The continuity equation for cosmic ray propagation is used to derive a set of linear equations interrelating the fluxes of multiply charged nuclei as observed at any particular part of the galaxy. The derivation leads to model independent definitions for cosmic ray storage time, mean density of target nuclei and effective mass traversed. The set of equations form a common framework for comparisons of theories and observations. As an illustration, it is shown that there exists a large class of propagation models which give the same result as the exponential path length model. The formalism is shown to accommodate dynamic as well as equilibrium models of production and propagation.

Golden, R. L.↗

NASA NTRS1975

A determination of the sea level muon spectrum using accelerator data and some implications

The differential sea-level muon spectrum is calculated from first principle for a pure beam of cosmic-ray protons cascading in the atmosphere by using a representation of the invariant cross section that describes the observed data from 6 GeV to 1500 GeV. This spectrum is compared with the observed muon spectrum to deduce information on the interaction characteristics of nuclei-nuclei collisions.

Badhwar, G. D.↗

NASA NTRS1975

An experiment to measure cosmic ray 2H and 3He in the 4-10 GV range

It is known that the mean matter traversed by cosmic rays, X, can be obtained from the observed ratio of the flux of daughter nuclei to that of the parent nuclei provided X is much less than the attenuation mean free of the daughter nuclei. This condition is well satisfied in the case of 2H and 3He. We propose to measure the 2H/1H and 3He/4He ratios, using a multiwire proportional counter array and a superconducting magnet to measure the rigidity, and a set of aerogel Cerenkov counters to measure the velocity, thus yielding the mass of the particle. Results of a Monte-Carlo calculation based on actual experimental conditions are presented to show the resolution of the instrument. The area solid angle of the telescope is 90 sq cm sr with an average maximum detectable momentum of 140 GV.

Badhwar, G. D.↗

NASA NTRS1975

Energetics of monopole production

The relativistic kinematics of monopole production and mechanisms of energy loss and gain for monopoles in free space and in the upper atmosphere are studied. It is shown that a monopole produced in a nuclear interaction must have a laboratory energy greater than about 200,000 GeV if its mass is greater than 600 GeV per sq cm. A study of energy loss mechanisms of such an energetic monopole in the earth's magnetic field and atmosphere rules out the possibility of observing such a monopole with the parameters observed by Price et al. (1975). The very low velocity of the observed monopole also makes an extraterrestrial production mechanism very unlikely.

Badhwar, G. D.↗

NASA NTRS1974

Rigidity spectrum of z greater than or equal to 3 cosmic-ray nuclei in the range 4-285 GV and a search for cosmic antimatter

A measurement, using the magnetic emulsion spectrometer system, of the differential rigidity spectrum of Z greater than or equal to 3 nuclei of the galactic cosmic radiation is presented. The system was flown on Aug. 22, 1969, from Palestine, Texas. The instrument floated above 125,000 feet for eight hours. The data in the rigidity range 8-285 GV can be represented by a power-law spectrum in rigidity, J(rho) = A rho to the minus gamma power, with the exponent gamma = 2.6 plus or minus 0.10. The spectrum in the range 15-285 GV is also described by the same exponent, gamma = 2.6 plus or minus 0.25. The data below 8 GV cannot be described by the same power law without invoking solar modulation. A set of nonunique parameters for modulation are given. Upper limit for the fraction of antimatter in the rigidity range 4-125 GV is .005 with 95% confidence limit.

Golden, R. L.↗

NASA NTRS1974

Relative abundances of positrons and antiprotons in the primary cosmic ray flux

Observations on the ratio of positrons to the electron-positron sum made in the 5 to 50 GeV range by Buffington et al. (1974) are used to put an upper limit on the ratio of antiprotons to protons at various energies. The calculation of the latter ratio is based on detailed measurements of the cross section of antiproton production up to intersecting storage ring energies.

Badhwar, G. D.↗